Showing papers on "Sodium sulfide published in 1972"

Absorption of sulfur oxides from flue gas

Abstract: A method is shown for removing sulfur dioxide from a hot flue gas by absorption of the sulfur dioxide in an aqueous solution or slurry containing no more than 40 wt.% of an alkali metal carbonate or bicarbonate, preferably sodium carbonate and/or sodium bicarbonate using a spray-dryer scrubber to produce a dry mixture of sodium sulfite, sodium sulfate, and sodium carbonate and/or bicarbonate. Such a mixture is directly suitable as a feed to a regeneration stage. It is particularly preferred to regenerate the absorbent and recover commercial sulfur values in a closed-cycle process by next treating the solid absorption product in a molten salt reduction step with a reducing agent, preferably a carbonaceous material, to reduce the sodium sulfite and sulfate to sodium sulfide. Concurrently, a source of oxygen is fed to the reducer to generate sufficient heat therein for the reduction step by a combustion reaction. In the subsequent aqueous reformation step, the resulting sodium sulfide-carbonate melt from the reduction step is dissolved in water and reacted with carbon dioxide or a carbon dioxide-yielding material to form hydrogen sulfide as a recoverable product for further processing and regenerate the sodium carbonate-bicarbonate absorbent.

Carbonation system for recovery of sodium base pulping liquor

Abstract: THIS INVENTION PROVIDE AN INTERGRATED CLOSED CARBONATION SYSTEM FOR RECOVERING SODIUM BASE SULFITE PULPING LIQUOR WHICH IS OF INTEREST CHEMICALLY, THERMALLY AND ECOLOGICALLY. THE SYSTEM INCLUDES IN COMBINATION (1) SMELT SOLUTIONS CONTAINING FROM 33 TO 67 MOL PERCENT SODIUM SULFIDE WITH THE BALANCE PRIMARILY SODIUM CARBONATE, (2) SELF-SUFFICIENCY IN CARBON DIOXIDE FOR DISPLACEMENT OF THE SULFIDE, (3) TEMPERATURES DURING CARBONATION OF FROM 140*-180*F., (4) AN INTERMEDIATE CONCENTRATION OF CO2 FOR CARBONATION, (5) SYSTEMS FOR CYCLING VARIOUS GAS STREAMS TO CONSERVE AND RESIDUE CARBON DIOXIDE WHILE STILL PURGING THE SYSTEM OF NITROGEN AND IN PARTICULAR THE RECYCLING OF PURGE GASES FROM A PRECARBONATION ZONE TO A MAIN CARBONATION ONE, (6) PRODUCTION OF GASES CONTAINING H2S AT A CONCENTRATION GREATER THAN 6% BY VOLUME SUITABLE FOR DIRECT COMBUSTION TO SO2, AND (7) PURGE GASES ESSENTIALLY FREE OF EITHER H2S, OR SO2.

Process for recovering antimony value out of spent catalyst

Abstract: Spent antimony halide catalyst used in the production of chlorofluoroalkane by the fluorination of chloroalkane is treated with water or mineral acid, and the organic layer is separated out of the aqueous layer which contains antimony value. The aqueous layer is treated with a metal such as iron, manganese, copper, zinc, tin, or their salts, or alternatively treated with hydrogen sulfide, sodium sulfide or ammonium sulfide, to precipitate antimony compounds.

Method of high yield semichemical pulp production

Abstract: DIUM HYDROXIDE OR IN THE FORM OF KRAFT WHITE LIQUOR, TO THE COOKED MIXTURE TO RAISE THE PH BETWEEN 9 AND 13; AND MECHANICALLY FIBERIZING IN THE PRESENCE OF THE SODIUM HYDROXIDE AND SPEND COOKING THE LIQOUR, THE COOKED COMMINUTED WOOD. THE RESULTING PULPS ARE USEFUL FOR MAKING UNBLEACHED STRUCTURAL PAPER, SUCH AS FLUTED MEDIUM FOR CORRUGATED BOARD, LIKE 9 POINT CORRUGATED MEDIUM. A PROCESS IS SET FORTH FOR PRODUCING PULP AT A YEILD OF 69 TO 85% WHICH COMPRISES; COMBINING IN A PRESSURE VESSEL, EITHER THE BATCH OR CONTINUOUS TYPE, COMMINUTED WOOD WITH A SOLUTION OF COOKING LIQUOR COMPRISING SODIUM IONS WHEREIN 60-100% THEREOF, MEASURED AS SODIUM OXIDE, IS SODIUM CARBONATE AND 0 TO 30% THEREOF IS SODIUM SULFIDE; COOKING THE MIXTURE UNDER PRESSURE AND HEAT UNTIL 40-15% OF THE ORGANIC COMPONENTS OF THE WOOD ARE SOLUBILIZED; ADDING SUFFICIENT SODIUM HYDROXIDE, EITHER AS SO-

Protein product and process of preparing it which comprises reacting poultry feather meal,lime and sodium sulfide

Abstract: A PROCESS OF PRODUCING A PROTEIN PRODUCT COMPRISING THE STEPS OF HEATING A REACTION MIXTURE OF 10 PARTS BY WEIGHT OF POULTRY FEATHER MEAL TO 1-2 PARTS LIME (CAO) AND TO 2-3 PARTS OF SODIUM SULFIDE (NA2S) AND OF 7-10 GALLONS OF WATER TO 10 POUNDS OF POULTRY FEATHER MEAL TO C TEMPERATURE RANGE OF 190*-212*F. FOR 3-5 HOURS; COOLING THE MIXTURE TO A PH RANGE OF 6.8-7.2 WITH AN ACID; AND SEPARATING THE SLUDGE FROM THE MIXTURE TO PRODUCE A CLEAR WATER SOLUBLE PRODUCT, A PROTEIN PRODUCT PRODUCED BY THE ABOVE PROCESS.

Process for bleaching kraft pulp with oxygen in the presence of white liquor from a kraft recovery system

Abstract: AN IMPROVED METHOD OF BLEACHING KRAFT PULP IN AN OXYGEN-BASED BLEACHING PROCESS IS DISCLOSED IN WHICH (A) WHITE LIQUOR FROM A KRAFT RECOVERY SYSTEM IS EMPLOYED AS A SOURCE OF ALKALI IN THE OXYGEN-BASED BLEACHING PROCESS WITHOUT ANY PRETREATMENT OF THE WHITE LIQUOR TO REMOVE SODIUM SULFIDE AND (B) THE EFFLUENT FROM THE OXYGENBASED BLEACHING PROCESS IS RECYCLED DIRECTLY TO THE KRAFT RECOVERY SYSTEM.

Hydrogen sulfide synthesis

Abstract: A PROCESS FOR THE SYNTHESIS OF HYDROGEN SULFIDE FREE OF CARBON DIOXIDE COMPRISING THE STEPS OF REACTING A SULFUR BEARING MATERIAL SUCH AS SODIUM SULFATE OR SODIUM SULFITE WITH OXYGEN, CARBON AND STREAM UNDER REDUCING CONDITIONS IN THE PRESENCE OF HYDROGEN SULFIDE TO PRODUCE SODIUM SULFIDE. THIS SODIUM SULFIDE IS THEN REACTED WITH ACID TO LIBERATE HYDROGEN SULFIDE.

Reactions of pyrylium salts with nucleophilic agents

Abstract: The reaction of γ-unsubstituted pyrylium salts with alkali-metal cyanides gives cyano- and carboxy-substituted pyrans and pyrylium salts, while the reaction with sodium sulfide gives dipyranyl sulfides. A phthalimide derivative of pyran is obtained from 2,6-diphenylpyrylium perchlorate and potassium phthalimide, while pyrylium cations react with zinc to give the corresponding dipyranyls.